2015 RAM 3500 wobble after 2" lift HELP!

[pinarello57]

Hello, I have a 2015 RAM 3500 LB 4X4 with 18,000 miles on it that drove perfectly prior to having a professionally installed 2" leveling lift with shock extenders and 1.5" wheel spacers all around. The truck seemed great until I hit 60mph, at 65-70 I het a wobble what intensifies as I a corner.  Really uncomfortable over 55mph.  I suspect the Caster, toe or maybe more is out although it was aligned (currently 2.1 total toe, caster is 3.7 L and 3.9 R).

 

Please help, I need good specs. because this isn't working for sure!

 

Thank you kindly!

[Moses Ludel]

pinarello57...Wobble on a beam axle is much like "kingpin shimmy".  This is often caused by loose ball-joints, but I do not believe this is happening with your truck...seems too new for bad ball-joints.

Other causes include not enough positive caster angle, but here you also fall within specification.  Your truck's caster reading is reasonable and shows a cross-caster correction as well.  Toe will not cause a wobble, if toe is off, it would be more apt to cause wander, pull or rapid tire wear.  You did not share camber, and this could exaggerate what I believe is the issue:  the 1.5" wheel spacers.  Camber on a newer Ram beam axle is usually in specification.

Installing 1.5" spacers widens track width, which was likely your goal to maintain center-of-gravity with the lift or clearance for oversized tires.  The lift is somewhat mild, did you need the wheel spacers for oversized or wider tires?  In any case, the spacers are a dramatic offset of the wheels, and they are likely causing your problem.

Note: Use of thick spacers like this changes the wheel offset, the steering axis inclination (SAI) and also the scrub radius.  It's possible that the geometry of your truck's front end is suffering from errors in each of these measurements.  The 1.5" wheel spacers could be the cause.

If you have the original tires and wheels, try temporarily mounting them on the truck without the spacers in place.  If this eliminates the wobble and shaky steering angle feedback on corners, you may have found the problem.  Wheel offset, SAI and scrub radius are crucial to handling and compliant steering geometry.  

Also, the speed at which your problem occurs is classic for tire imbalance or out-of-round condition.  The spacers could be creating imbalance symptoms, or the tire balance may be off.  Discuss this with your tire store.

I make a point of getting the correct wheel rim offset when selecting aftermarket wheels.  (I've never used spacers, and I always establish offset with the correct wheel rim choice.)  I'm running heavy 37"x12.5"x17" BFG KO2 tires and Raceline rims on my '05 Ram without any complications (using a 4-inch chassis/suspension lift).  This is only possible with the correct wheel rim offset and creating the proper SAI and scrub radius.  Balance is critical with a wheel/tire unsprung weight mass like this...

Let us know how this works out...

Moses

[biggman100]

Moses, something to add, as i recently learned. Not all spacers are made equally, being that, some of the less expensive ones aren't always truly round, as we found out in an experiment on my brothers truck. He had an odd shimmy, but it only seemed to be in one wheel, but, when he changed to new all billet spacers, it got even worse, then he went to another, higher priced brand, still billet, and, in 1300 miles, not once has the shimmy came back. We took his original spacer and put in dead center on a lathe, and the inside diameter was out of round more than 20MM, then we tried 2 of the second pair he bought, and one, the outside was out almost 45MM, another one, the center hole was almost egg shaped. Of course, both companies he bought the spacers from say it was his fault, that he installed them wrong and caused them to be damaged, so, we bought a second pair from the first company, and they were even worse (another thing to note, on the original pair, not even the center hole was exactly the same size, 3 were off by roughly 4MM from each other, but, one was 15MM under sized from the rest). We also seen where one adapter was actually 12MM thinner than the rest, as well. Another thing i have recently learned is, some wheels are "concentric" to fit certain hubs, and if the spacer isnt concentric and the wheel is, that will also cause a vibration, or vice versa. Yes, i know, a pricey experiment, but, my brother builds dirt modified's for customers, so he can afford a bit of experimenting (just don't get me started on his 2 year long, holley 2 vs 4 barrel on a 2wd Chevy 1500 experiment, i might be here all day).